Find Posts By Topic

King County Informational open house Feb. 23 for upcoming summertime construction and trail closures at Discovery Park

Attend a Feb. 23 open house at the Discovery Park Environmental Learning Center in Seattle to learn about summertime construction work on water supply systems planned in the park by the King County Wastewater Treatment Division. If there is inclement weather, the event will be rescheduled for Saturday, March 2.

Work this summer by the King County Wastewater Treatment Division (WTD) to modify an underground water reservoir in Seattle’s Discovery Park will require partial closures to portions of two hiking trails.

An open house on Feb. 23 at the Discovery Park Environmental Learning Center in Seattle will provide details of the work, which will take three to five months to complete and require partial closures along the Loop and Capehart trails.

The open house runs from 10 a.m. to noon at the learning center, 3801 Discovery Park Blvd.

King County is protecting public health with upgrades to the underground water-storage facility by providing safe and efficient access for annual inspections, and by meeting current standards for protecting water sources.

Construction will involve demolishing concrete access hatches to the existing reservoirs, installing new interior pipes, and building a new roof and access hatch to protect the entryway from rain and debris. An outfall pipe will be installed in an excavated trench, which is then backfilled and replanted.

The water system carries both potable (drinkable) and non-potable water. Potable water is used at West Point Treatment Plant, in water fountains throughout Discovery Park, and at the West Point Lighthouse. Non-potable water is used at the treatment plant for industrial processes.

Contractors will install air gaps above each water tank to prevent mixing of the potable and non-potable water, and to protect equipment. Crews will also install a 460-foot-long pipe to carry excess water to a discharge site in the unlikely event of an overflow.

The County recognizes that Discovery Park is a popular location for trail users, and nature and bird enthusiasts. The WTD and Seattle Parks have developed tree protection and vegetation restoration plans as a part of this project, which will require some vegetation removal.

The vegetation will be replaced with a variety of plants and trees that blend with the natural environment and supports the park’s wildlife. Work on the pipe will begin after the bird nesting season ends in August to mitigate impacts on birds.

For more information on this project, visit WTD’s West Point project web page. For more information on the open house or to request accommodations, contact Eunice Lee: or 206-263-1614.